Heretofore it has been the desire of those skilled in the art to use a plurality of engines to drive a simple reduction gear box that was capable of delivering power to means to be driven. In such devices the object was to use the engine to mount and drive accessory devices. In most such prior art structures there was no desire to segregate internal portions of such gear box such that the engine input of one could not, if damaged, contaminate the other. There has been various provisions in such prior art structures to remotely locate the engines due to certain requirements, as with turbine type powerplants to prevent shrapenal of any disintegrating powerplant from affecting any other or for that matter any engine fire of one from spreading to the other. It is in the improvement of such drive systems that the disclosure of this invention hereinafter will be found beneficial to those skilled in the art.